Below the Threshold: China's Gray Zone Campaign Against Taiwan
The People’s Republic of China has been conducting a sustained campaign of pressure against Taiwan that falls below the threshold of armed attack and above the threshold of normal competitive statecraft. This gray zone — the space between peace and war where coercion operates through ambiguity, exhaustion, and the deliberate exploitation of thresholds — has been the primary arena of Chinese pressure on Taiwan for years and is the operating environment that Taiwan’s defense establishment spends more of its daily attention managing than any invasion scenario.
The air component of the gray zone campaign has been documented in extraordinary detail by Taiwan’s Ministry of National Defense, which publishes daily reports on PLA Air Force incursions into Taiwan’s Air Defense Identification Zone. The ADIZ is not territorial airspace — it is a self-declared zone, not recognized in international law, within which Taiwan requires identification and communication from entering aircraft. The PLA does not recognize the zone and has been systematically violating it at increasing scale since 2020. The daily interceptions — Taiwan’s fighters scrambling to identify and shadow Chinese aircraft that approach but do not cross the territorial airspace boundary — impose a maintenance and readiness cost on Taiwan’s air force that is significant and cumulative. Fighter aircraft have finite airframe hours. Pilots have finite fatigue tolerance. The gray zone campaign is designed to consume both.
The maritime gray zone operation parallels the air campaign. Chinese coast guard and maritime militia vessels — the latter being fishing boats crewed by military reservists and operating under PLAN direction while maintaining the legal fiction of civilian activity — operate in waters that Taiwan claims and in the approaches to Taiwan-administered islands in the South China Sea and the East China Sea. The maritime militia concept, perfected in the South China Sea against Philippine and Vietnamese claims, is being applied against Taiwan’s peripheral maritime territory in ways that create precedents, exhaust patrol resources, and establish Chinese presence without triggering a military response.
The cognitive dimension of the gray zone campaign is the most difficult to measure and the most significant in its long-term implications. Chinese information operations targeting Taiwan’s population — disinformation campaigns designed to deepen social divisions, undermine confidence in the government, spread defeatism about the possibility of successful defense, and cultivate pro-unification political sentiment — have been running continuously for decades and have been amplified by social media platforms that provide simultaneous scale and deniability. Taiwan’s high internet penetration, its vibrant social media culture, and its open information environment are both strengths of its democracy and vulnerabilities to information operations by a state actor with the resources and the intent to exploit them.
The economic coercion dimension has been deployed selectively. China has banned imports of specific Taiwanese agricultural products — pineapples, grouper fish, certain wines — in ways that impose targeted pain on specific industries and constituencies without triggering a response that would require a formal diplomatic response or military posture adjustment. The selective nature of the bans communicates Beijing’s capacity for broader economic coercion while stopping short of actions that would consolidate Taiwanese political opposition or trigger allied responses.
The gray zone campaign serves multiple strategic objectives simultaneously. It imposes costs on Taiwan’s defense resources, degrades the morale of Taiwan’s population and defense establishment through sustained low-level pressure, creates precedents for Chinese presence in claimed areas, and tests the responses of Taiwan’s allies without triggering the alliance responses that a clear armed attack would produce. It is not a substitute for the military option that Chinese leadership has explicitly retained. It is the operating environment within which that option is being prepared.
The fundamental problem for Taiwan in responding to the gray zone campaign is that each individual incident is below the threshold that justifies a response severe enough to impose real costs on China. The accumulation of below-threshold incidents produces strategic effects that no single incident would produce. This asymmetry — China controls the pace and intensity of pressure while Taiwan must respond to each incident on its merits — gives Beijing a structural advantage in the gray zone competition that Taiwan cannot fully offset through its own actions.